1. Field of the Invention
The present invention relates to abrasive blast wheels for cleaning work pieces and more specifically, to a simplified assembly that allows for easier replacement of worn throwing blades, while minimizing the number of components.
2. Description of the Prior Art
Abrasive blast wheels are typically used to deliver abrasive materials at high velocities onto a work piece in order to clean the work piece. The blast wheels are rotationally driven by a motor or other rotational driving device capable of attaining the high speed rotation required in order to properly clean the targeted work piece. Blast wheels generally include several vanes or blades that attach to an impeller or mounting plate. In general, the blades must be a separate component because they must be replaced periodically due to excessive wear caused by the abrasive materials.
A typical blast wheel includes a mounting plate for securing the blades. In general, the prior designs require either a specific tool for removing and replacing the blades, or additional components that cooperate to lock the blade in place. For example, a pin or lug may be inserted into the mounting plate after the blade is installed to prevent radially outward movement of the blades. In general, such designs are either difficult to service or are costly due to the fact that they require additional components.
Another type of blast wheel secures the blades to a mounting plate by inserting the blades from the center of the wheel radially outward into the mounting plate. The mounting plate includes a ridge that prevents further outward movement of the blades. Radially inward movement is then prevented by an additional inner component that contacts the innermost portion of the blade to secure it to the mounting plate. Such a design is again difficult to service due to the fact that a number of components, such as the impeller and supply spout that supplies the abrasive material, must be removed to provide enough clearance to remove the blades.
Other blast wheels attempt to simplify the service process by sliding the blades radially inward into slots on the mounting plate. The blades are then secured by an additional hub component that prevents radially outward movement of the blades while also allowing them to be removed. The hub includes a slot and may be rotated relative to the mounting plate such that the slot aligns with a blade, thereby allowing that particular blade to be removed from the plate. This design reduces the number of components required to secure the blades but requires that each blade be removed one at a time. Each time a blade is replaced, the hub must be rotated until it aligns with the next blade to be removed.
In view of the foregoing limitations and shortcomings of the prior art devices, as well as other disadvantages not specifically mentioned above, it should be apparent that there still exists a need in the art for an improved abrasive blast wheel which is inexpensive to make and easy to replace the worn blades.
It is therefore a primary object of this invention to fulfill that need by providing an abrasive blast wheel that provides a more efficient replacement process for replacing worn blades.
It is another object of this invention to provide a blast wheel that allows multiple blades to be removed and replaced simultaneously.
It is a further object of this invention to provide a blast wheel that requires fewer components for retaining the throwing blades within the assembly.
It is another object of this invention to secure the blades without any screws or pins attaching them to the assembly.
It is yet another object of this invention to secure all the blades with one continuous ring that is easily removed from the blast wheel.